Fuel tanks

ABSTRACT

A fuel tank for a motor vehicle engine has a vent pipe for fuel or vapour overflow leading from an upper end of the tank filler pipe to a liquid separator chamber housed within the tank. The vent pipe extends from the separator chamber to a container holding activated carbon particles for adsorbing fuel vapour and thence to an air cleanser for the engine carburettor.

1451 Sept. 11, 1973 United States Patent 11 1 Hunt .lllll-lln -t T No mmm sw 3,675,634 7/1972 Tatsutomi.....1........ 2,860,656 11/1958Eshbaugh....

3,698,160 10/1972 Hunter.....

3,542,239 11/1970 Latva1a....

Allan Frederick Hunt, Solihull,

Chrysler United Kingdom Limited,

m 0 new S n 0 ME L Tm w Lm ms EC U s Fm A MN 4 57 7 [1 1 PrimaryExaminer-Laurence M. Goodridge [22] Filed: Oct. 5, 1971 AssistantExaminer-Cort Flint 211 Appl. No.2 186,633

Attorney-John A. Mawhinney [30] Foreign Application Priority Data Oct.16, 1970 Great Britain...................

ABSTRACT A fuel tank for a motor vehicle engine has a vent pipe for fuelor vapour overflow leading from an upper end of the tank filler pipe toa liquid separator chamber housed within the tank, The vent pipe extendsfrom the 58 mm mu 2 ,m 62 30M.- M5 2 M3 M1 0 n mmn "a .r "3 me Us .I..Cl C d s a UmF 11.11 2 8 555 [[1 separator chamber to a contamer holdmgact1vated carbon particles for adsorbing fuel vapour and thence to anair cleanser for the engine carburettor.

References Cited UNITED STATES PATENTS 3,191,587 6/1965 123/1367Claims,lDrawingFigure PATENTEI] SEPI H875 A! 22 i H 27 FUEL TANKS Thisinvention relates to fuel tanks for motor vehicle engines.

The invention provides a fuel tank for a motor vehicle engine having afiller pipe extending upwardly of the tank, a cap for sealing the fillerpipe, an outletpipe connected to the tank for delivery of fuel from thetank a vent pipe which opens into the tiller pipe above the tank forventing air into the tank and receiving excess liquid and/or vaporisedfuel, a device located in the vent pipe for collecting fuel vapourpassing along the vent pipe from the filler pipe and a liquid separatorlocated in the vent pipe between the filler pipe and said device forcollecting liquid fuel passing along the vent pipe from the filler pipewhich separator is housed within the fuel tank.

Preferably the liquid separator comprises a separate chamber in the fueltank, the vent pipe from the filler pipe opens into the bottom of thechamber and the vent pipe to the vapour collection device leads from thetop of the chamber so that any liquid collected in the chamber syphonsback to the filler pipe when fuel is removed from the tank.

It is also preferred that the vent pipe is connected to the air inletside of a carburettor for the vehicle engine.

In any of the above arrangements the device for collecting fuel vapourmay include means for adsorbing the vapour.

In the latter arrangement means may be provided for supplying heated airto the vapour collection device to revaporise the fuel and pass thevaporised fuel to the air inlet of the carburettor.

The means for heating the air may comprise a heating jacket encircling apart of an exhaust system for the engine which jacket has an opening forreceivingair and is connected to said device for removing fuel vapour sothat air is drawn through the jacket past said device to the carburettorinlet when the engine is running and the heated air removes the fuelfrom said adsorption means.

In any of the above arrangements a plurality of conduits may lead fromthe top of the tank to the upper end of the tiller pipe to delivervapour from the tank to the filler pipe. Said plurality of pipes may beconnected to a manifold and a single pipe may lead from the manifold tothe upper end of the filler pipe.

The following is a description of a specific embodiment of the inventionreference being made to the accompanying drawing which is a diagrammaticview of a vehicle fuel tank and associated system.

Referring to the drawing, a fuel tank for a motor vehicle is indicatedat 10. The tank has a filler pipe 11 extending from one side thereofwhich is turned upwardly at an elbow l2 and leads to an open neck 13located above the top of the tank. The neck 13 is sealed by a filler cap14. 'Fuel is drawn from the tank and supplied to the engine carburettorthrough a conduit 15.

Air is vented into the tank by a vent pipe 16 which leads into thefiller pipe 11 through a fluid tight joint at the elbow 12 through anopening 17. The vent pipe extends up the filler pipe and terminatesadjacent the neck 13. A closed liquid separator chamber 18 is housedwithin the tank 10 and is secured to the underside of the top wall ofthe tank. The vent pipe leads through the top wall of the tank into thechamber 18 and stops just short of the bottom of the chamber.

A continuation of the vent pipe leads from the upper part of the chamberout through the top wall of the tank through a container 19 filled withactivated carbon granules 20 for adsorbing fuel vapour and thence to anair cleaner 21 for a carburettor 22 of the vehicle engine 23 throughwhich air passes before entering the carburettor.

if the temperature of the fuel rises causing vaporisation of the fuelwhen the vehicle engine is not running, the fuel vapour can pass throughthe vent pipe 16 and the chamber 18 to the container 19 where it isadsorbed by the activated carbon. If the tank is full or nearly full andthe temperature of the fuel rises, the fuel may expand until the fuellevel rises above the open end of the vent pipe 16 in the filler pipe11. The liquid fuel will then pass down the vent pipe and will becollected in the chamber 18. When fuel is withdrawn from the tankthrough the conduit 15 air vents into the tank through the vent pipe 16because the depression. caused above the fuel in the tank is greaterthan the air depression in the air cleaner. Any liquid fuel collected inthe chamber 18 will then syphon back to the filler pipe and thence draindown to the tank.

To avoid trapping of pockets of vapour in the tank four conduits 24 leadfrom the top of the tank adjacent the four corners thereof to a manifold25 when the conduits are collected into a single conduit 26 which leadsthrough or has a fluid tight seal in a hole 27 in the elbow 12 of thefiller pipe and thence up the filler pipe to stop just short of the openend of the vent pipe 16. Thus any vapour collecting in the tank can passinto the filler pipe.

The container 19 for the activated carbon is connected by a pipe 28 to aheating jacket 29 which encircles a branch 30 of an exhaust system forthe vehicle engine. The jacket 29 has an opening 31 for receiving air sothat when the engine is running the resulting air depression in the aircleaner draws air into the heating jacket 29 where it is heated andthence to the container 19. The hot air passing through the carbongranules causes the adsorbed fuel to re-vaporise and the fuel vapourpasses to the air cleaner and thence into the engine carburettor. Thusthe fuel vapour does not escape to atmosphere.

It will be appreciated that many modifications may be made to the aboveembodiment without departing from the scope of the invention. Forexample the ambient temperature of the engine compartment may besufficiently high to re-vaporise condensed fuel vapour from theactivated carbon particles 20 in the container 19 in which case theheater jacket 29 and pipe 28 can be dispensed with. The container 19 isprovided with an inlet for air from the engine compartment.

I claim:

1. A fuel tank for a motor vehicle engine having a filler pipe extendingupwardly of the tank, a cap for sealing the filler pipe, an outlet pipeconnected to the tank for delivery of fuel from the tank, a vent pipewhich opens into the tiller pipe above the tank for venting air into thetank and.receiving excess liquid and/or vaporized fuel, a device locatedin the vent pipe for collecting fuel vapour passing along the vent pipefrom the filler pipe and a liquid separator located in the vent pipebetween the tiller pipe and said device for collecting liquid fuelpassing alongthe ventpipe from the filler pipe which separator is housedwithin the fuel tank, said liquid separator comprising :a separatechamber in the fuel tank and the vent pipe from the tiller pipe opensinto the bottom of the chamber and the vent pipe to the vapourcollecting device leads from the top of the chamber so that any liquidcollected in the chamber syphons back to the filler pipe when fuel isremoved from the tank.

2. A fuel tank as claimed in claim 1 wherein the vent pipe is connectedto the air inlet side of a carburettor for the vehicle engine.

3. A fuel tank as claimed in claim 1 wherein the device for collectingfuel vapour includes means for adsorbing the vapour. 4. A fuel tank asclaimed in claim 3 wherein means are provided for supplying heated airto the vapour collection device to revaporise the fuel and pass thevaporised fuel to the air inlet of the carburettor.

5. A fuel tank as claimed in claim 4 wherein the means for heating theair comprise a heating jacket encircling a part of an exhaust system forthe engine which jacket has an opening for receiving air and isconnected to said device for removing fuel vapour so that air is drawnthrough the jacket past said device to the carburettor inlet when theengine is running and the heated air removes the fuel from saidadsorption means.

6. A fuel tank as claimed in claim 1 wherein a plurality of conduitslead from the top of the tank to the upper end of the filler pipe todeliver vapour from the tank to the filler pipe.

7. A fuel tank as claimed in claim 6 wherein said plurality of pipes areconnected to a manifold and a single pipe leads from the manifold to theupper end of the filler pipe.

1. A fuel tank for a motor vehicle engine having a filler pipe extendingupwardly of the tank, a cap for sealing the filler pipe, an outlet pipeconnected to the tank for delivery of fuel from the tank, a vent pipewhich opens into the filler pipe above the tank for venting air into thetank and receiving excess liquid and/or vaporized fuel, a device locatedin the vent pipe for collecting fuel vapour passing along the vent pipefrom the filler pipe and a liquid separator located in the vent pipebetween the filler pipe and said device for collecting liquid fuelpassing along the vent pipe from the filler pipe which separator ishoused within the fuel tank, said liquid separator comprising a separatechamber in the fuel tank and the vent pipe from the filler pipe opensinto the bottom of the chamber and the vent pipe to the vapourcollecting device leads from the top of the chamber so that any liquidcollected in the chamber syphons bAck to the filler pipe when fuel isremoved from the tank.
 2. A fuel tank as claimed in claim 1 wherein thevent pipe is connected to the air inlet side of a carburettor for thevehicle engine.
 3. A fuel tank as claimed in claim 1 wherein the devicefor collecting fuel vapour includes means for adsorbing the vapour.
 4. Afuel tank as claimed in claim 3 wherein means are provided for supplyingheated air to the vapour collection device to revaporise the fuel andpass the vaporised fuel to the air inlet of the carburettor.
 5. A fueltank as claimed in claim 4 wherein the means for heating the aircomprise a heating jacket encircling a part of an exhaust system for theengine which jacket has an opening for receiving air and is connected tosaid device for removing fuel vapour so that air is drawn through thejacket past said device to the carburettor inlet when the engine isrunning and the heated air removes the fuel from said adsorption means.6. A fuel tank as claimed in claim 1 wherein a plurality of conduitslead from the top of the tank to the upper end of the filler pipe todeliver vapour from the tank to the filler pipe.
 7. A fuel tank asclaimed in claim 6 wherein said plurality of pipes are connected to amanifold and a single pipe leads from the manifold to the upper end ofthe filler pipe.